Traveling control device and traveling control program for work vehicle or control device and control program for work vehicle

Abstract

A traveling control device and a traveling control program for a work vehicle in which a change in a control quantity due to an effect of vehicle body vibrations is small, fixing the desired control quantity is possible, and the control quantity can be matched with the operator's feel. A travel control program in which a first line on which the speed ratio reduces corresponding to a change in the operation stroke, a second line having hysteresis with respect to the first line and on which the speed ratio increases corresponding to a change in the operation stroke, and third lines on which the speed ratio changes corresponding to the change in the operation stroke and the change in speed ratio with respect to the change in the operation stroke is smaller than that of the first and the second line are set is installed in the control device.

1. A work vehicle travel control device that controls travel of a work vehicle in accordance with set lines indicating a relationship between an operation stroke of an operation device and a speed ratio of left and right crawler tracks or wheels of a vehicle body, wherein
 a first line on which the speed ratio decreases corresponding to a change in the operation stroke, 
 a second line that has hysteresis with respect to the first line and on which the speed ratio increases corresponding to a change in the operation stroke, and 
 third lines on which the speed ratio changes corresponding to a change in the operation stroke and the change in the speed ratio with respect to the change in the operation stroke is smaller than that of the first line and that of the second line, are set, and 
 control means is provided for controlling the speed ratio to decrease in accordance with the first line when the operation device is operated from a point on the first line in a direction that the speed ratio decreases, 
 to increase in accordance with the second line when the operation device is operated from a point on the second line in a direction that the speed ratio increases, 
 to change in accordance with the third lines when the operation device is operated from a point on the first line in a direction that the speed ratio increases, or when the operation device is operated from a point on the second line in a direction that the speed ratio decreases. 
 
     
     
       2. The work vehicle travel control device according to  claim 1 , wherein
 the second line is set so that the change in the speed ratio with respect to the change in the operation stroke is smaller than that of the first line, and 
 the third lines are set so that the larger the speed ratio on a line the larger the range of the operation stroke. 
 
     
     
       3. The work vehicle travel control device according to  claim 1 , for controlling the speed ratio so that a target speed ratio is reached after a time delay from a time the operation device is operated, wherein
 the speed ratio is controlled so that the time delay when the speed ratio is controlled in accordance with the third lines is smaller than the time delay when the speed ratio is controlled in accordance with the first line or the second line. 
 
     
     
       4. The work vehicle travel control device according to  claim 3 , wherein
 drive shafts of hydraulic motors are connected to the left and the right crawler tracks or the wheels of the vehicle body, 
 the operation device is an electrical operation device that outputs an electrical signal corresponding to the operation stroke, and 
 a controller receives the outputted electrical signal from the operation device, and controls the speed ratio by changing a rate of rotation of the hydraulic motors in accordance with the operation stroke. 
 
     
     
       5. The work vehicle travel control device according to  claim 1 , wherein
 drive shafts of hydraulic motors are connected to the left and the right crawler tracks or the wheels of the vehicle body, 
 the operation device is an electrical operation device that outputs an electrical signal corresponding to the operation stroke, and 
 a controller receives the outputted electrical signal from the operation device, and controls the speed ratio by changing a rate of rotation of the hydraulic motors in accordance with the operation stroke. 
 
     
     
       6. A travel control program stored in a non-transitory readable storage medium, the travel control program for a work vehicle in which lines indicating a relationship between an operation stroke of an operation device and a speed ratio of left and right crawler tracks or wheels on a vehicle body are set as specified below, and comprising instructions which when executed in a travel control device of a work vehicle cause the work vehicle to operate as specified below:
 1) a first line on which the speed ratio decreases corresponding to a change in the operation stroke, 
 a second line that has hysteresis with respect to the first line and on which the speed ratio increases corresponding to a change in the operation stroke, and 
 third lines on which the speed ratio changes corresponding to a change in the operation stroke and the change in the speed ratio with respect to the change in the operation stroke is smaller than that of the first line and that of the second line, are set, 
 2) when the operation device is operated from a point on the first line in a direction that the speed ratio decreases, the speed ratio is calculated in accordance with the first line, 
 3) when the operation device is operated from a point on the second line in a direction that the speed ratio increases, the speed ratio is calculated in accordance with the second line, 
 4) when the operation device is operated from a point on the first line in a direction that the speed ratio increases, or when the operation device is operated from a point on the second line in a direction that the speed ratio decreases, the speed ratio is calculated in accordance with the third lines. 
 
     
     
       7. The travel control program for the work vehicle according to  claim 6 , for generating a control electrical signal so that a calculated target speed ratio is reached with a time delay, wherein
 the control electrical signal is generated so that the time delay when the speed ratio is calculated in accordance with the third lines is smaller than the time delay when the seed ratio is calculated in accordance with the first line or the second line. 
 
     
     
       8. The work vehicle travel control program according to  claim 6 , wherein
 the second line is set so that the change in the speed ratio with respect to the change in the operation stroke is smaller than that of the first line, and 
 the third lines are set so that the larger the speed ratio on a line the larger the range of the operation stroke. 
 
     
     
       9. A work vehicle travel control device that controls a control quantity of a work vehicle in accordance with set lines indicating a relationship between an operation quantity of an operation device and the control quantity, wherein
 a first line on which the control quantity changes corresponding to an increase in the operation quantity, 
 a second line that has hysteresis with respect to the first line and on which the control quantity changes corresponding to a decrease in the operation quantity, and 
 third lines on which the control quantity changes corresponding to a change in the operation quantity and the change in the control quantity corresponding to the change in the operation quantity is smaller than that of the first line and that of the second line, are set, and 
 control means is provided for controlling the control quantity 
 to change in accordance with the first line when the operation device is operated from a point on the first line in a direction that the operation quantity increases, 
 to change in accordance with the second line when the operation device is operated from a point on the second line in a direction that the operation quantity decreases, 
 to change in accordance with the third lines when the operation device is operated from a point on the first line in the direction that the operation quantity decreases, or when the operation device is operated from a point on the second line in the direction that the operation quantity increases. 
 
     
     
       10. A control program stored in a non-transitory readable storage medium, the control program for a work vehicle in which lines indicating a relationship between an operation quantity of an operation device and a control quantity are set as specified below, and comprising instructions which when executed in a control device of the work vehicle cause the work vehicle to operate as specified below:
 1) a first line on which the control quantity changes corresponding to an increase in the operation quantity, 
 a second line that has hysteresis with respect to the first line and on which the control quantity changes corresponding to a decrease in the operation quantity, and 
 third lines on which the control quantity changes corresponding to a change in the operation quantity and the change in control quantity corresponding to the change in the operation quantity is smaller than that of the first line and that of the second line, are set, 
 2) when the operation device is operated in a direction that the operation quantity increases from a point on the first line, the control quantity is calculated in accordance with the first line, 
 3) when the operation device is operated in a direction that the operation quantity decreases from a point on the second line, the control quantity is calculated in accordance with the second line, and 
 4) when the operation device is operated in a direction that the control quantity decreases from a point on the first line, or when the operation device is operated in a direction that the control quantity increases from a point on the second line, the control quantity is calculated in accordance with the third lines.